The FlatCAM Shell window is shown at startup when FlatCAM loads. It can be
closed and re-opened at any time without loss of data by clicking on the
close button on the top right edge of the window and selecting
Tool→Command Line from the main menu respectively.

It is divided into 2 sections, an output section on the top and an input
section on the bottom. A record of previously issued commands is shown in
the output section along with their results and other information that
FlatCAM might provide. Distinction between types of data in the output
section is done by color coding.

To issue a command, type it in the input section and hit Enter. If the
command consists of multiple lines, use Shift-Enter to insert a new
line without issuing the command.

The Shell uses the TCL language. TCL provides the simples posible syntax
and requires no learning at all for isuing the basic FlatCAM commands.
Nonetheless, TCL is a powerfull language that enables the users to create
their own complex functionality if desired.

Issuing a command is as simple as typing its name and hitting the
Enter key. For example:

new

This the same as clicking on File→New in the main window menu.

If a command requires additional information, it is given immediately
after the command name and a space. For example, to open the gerber
file mygerber.gbr:

open_gerber mygerber.gbr

Sometimes a command will have optional parameters, this is, if you
provide it it will use it, otherwise it will use some default value.
For example:

isolate mygerber.gbr -tooldia 0.04

This would create isolation routing geometry for the mygerber.gbr
gerber object with a tool diameter of 0.04 inches (or mm, depending on
the project settings). Otherwise, if you run:

isolate mygerber.gbr

The same action will be performed but the tool diameter will be taken
from the default value set for that object (If it is a new object, its
default values will be set from the project options.)